In a patch I copied some lib files from data-values-value-view and data-values submodules to the main repo, thinking I just removed it from submodule later. When trying to remove it, it turned out that they are used in the submodules and thus we can't drop them. The copied code is untested because the qunit tests are not moved to wikibase.

There are several solutions to this. One thing we can do for now (thanks to @Jakob_WMDE ) is symlinks but later we should rewrite linkitem to decouple them from repo js codebase.